Monohedotrochus capensis (Gardiner, 1904) Filander & Kitahara & Cairns & Sink & Lombard, 2021

Filander, Zoleka N., Kitahara, Marcelo V., Cairns, Stephen D., Sink, Kerry J. & Lombard, Amanda T., 2021, Azooxanthellate Scleractinia (Cnidaria, Anthozoa) from South Africa, ZooKeys 1066, pp. 1-198 : 1

Monohedotrochus capensis (Gardiner, 1904) comb. nov.

Fig. 4I-K

Caryophyllia capensis Gardiner, 1904: 113-114, pl. 1, fig. 4A-D. - Boshoff 1981: 36. -Zibrowius and Gill 1990: 44.

Desmophyllum cristagalli . - Boshoff 1981: 37.

Balanophyllia capensis . - Boshoff 1981: 40 (in part).

Paraconotrochus capensis . -Cairns and Parker 1992: 21.

Type locality.

Off East London, South Africa (33°03'00"S, 27°57'00"E); 59 m ( Gardiner 1904).

Type material.

The holotype is lodged at the NMNH.

Material examined.

SAMC_A072992 (1 specimen): Southern margin, other locality data unknown. SAMC_A073228 (1 specimen): Southern margin, False Bay; depth unknown. SAMC_A073233 (1 specimen): Southern margin, 14 km from Cape Point/ 10 km off Buffels Wes Estuary, 34°13'59.99"S, 18°30'00.00"E; 42 m. SAM_A073245 (2 specimens): Eastern margin, 34 km off Coffee Bay / 7 km off Ntlonyane Estuary, 32°15'11.99"S, 28°57'42.00"E ; 47 m. SAMC_A088924 (1 specimen): Southern margin, 23 km from Kidds Beach/ 24 km off Ncera Estuary, 33°18'01.37"S, 27°51'30.58"E; 247- 147m. SAMC_A088927 (1 specimen): Southern margin, 92 km from Oubosstrand/ 89 km off Tsitsikamma Estuary, 34°53'21.93"S, 24°06'56.47"E; 355 m. SAM_A090072 (1 specimen): Western margin, 13 km from Pringle Bay /off Buffels Oos Estuary, 34°18'36.00"S, 18°42'53.99"E ; 71 m. SAMC_A090073 (1 specimen): Western margin, 23 km from Pringle Bay / 20 km off Buffels Oos Estuary, 34°10'05.99"S, 18°47'03.00"E ; 36 m. SAMC_A090074 (2 specimens): Eastern margin, 34 km from Coffee Bay / 7 km off Ntlonyane Estuary, 32°15'11.99"S, 28°57'42.00"E ; 47 m. SAMC_A090075 (1 specimen): Western margin, 49 km from Cape Point/ 51 km off Buffels Wes Estuary, 34°43'18.00"S, 18°12'29.99"E; 360- 365 m. SAMC_A090076 (1 specimen): Southern margin, 16 km from Cape Point/off Buffels Wes Estuary, 34°15'00.00"S, 18°36'00.00"E; 51 m. SAMC_A090078 (1 specimen): Southern margin, 14 km from Cape Point/ 10 km off Buffels Wes Estuary, 34°13'59.99"S, 18°30'00.00"E; 42 m. SAMC_A090081 (1 specimen): Southern margin, 12 km from Pringle Bay / 11 km off Buffels Oos Estuary, 34°16'59.99"S, 18°45'00.00"E ; 58 m. SAMC_A090140 (1 specimen): Southern margin, 92 km from Oubosstrand/ 89 km off Tsitsikamma Estuary, 34°53'21.93"S, 24°06'56.47"E; 355 m. SAM_H1365 (2 specimens): Southern margin, 28 km from Port Alfred / 3 km off Old Woman’s Estuary, 33°30'00.00"S, 27°08'59.99"E ; 40 m. SAM_H1366 (1 specimen): Southern margin, 5 km from East London / 3 km off Blind Estuary, 33°00'13.79"S, 27°56'59.99"E ; 59 m. SAM_H1374 (7 specimens): Southern margin, 241 km from Agulhas/ 247 km off De Mond-Heuningnes Estuary, 36°40'00.00"S, 21°25'59.99"E; 200 m. SAM_H1406 (2 specimens): Western margin, off Somerset West; depth unknown. SAM_H1439 (1 specimen): Southern margin, 25 km from Gonubie/ 24 km off Gqunube Estuary, 33°06'17.99"S, 28°10'59.99"E; 155 m. SAM_H1474 (1 specimen): Southern margin, 11 km from East London / 5 km off Gouda Estuary, 33°05'03.24"S, 27°49'33.40"E ; 146- 238 m. SAM_H3060 (1 specimen): Southern margin, 28 km from Gonubie/ 27 km off Buffalo Estuary, 33°09'29.99"S, 28°03'06.00"E; 86 m. SAM_H3061 (4 specimens): Southern margin, 28 km from Port Alfred / 3 km off Old Woman’s Estuary, 33°30'00.00"S, 27°08'59.99"E ; 93 m. SAM_H3210 (4 specimens): Eastern margin, 30 km from Scottburgh/ 20 km off Fafa Estuary, 30°33'24.00"S, 30°48'35.99"E; 690 m. SAM_H3211 (1 specimen): Eastern margin, 17 km from Margate/off Boboyi Estuary, 30°53'24.00"S, 30°31'41.99"E; 850 m. SAM_H3398 (2 specimens): Southern margin, 11 km from Gansbaai/ 38 km off Bot River Lagoon, 34°39'27.93"S, 19°17'03.00"E ; 36 m. ORI_DIIIa2 (2 specimens), ORI_DIIId1 (2 specimens), ORI_EIa4_2 (5 specimens): Eastern margin, other locality data unknown. USNM 100854 (1 specimen): Southern margin, 5 km from Port Elizabeth / 3 km off Bakens River Estuary, 33°56'52.31"S, 25°37'20.70"E ; depth unknown.

Imagery data.

BMNH 1939.7.20.37-39 (1 specimen), BMNH 1950.1.11.63 (1 specimen): South Africa, other locality data unknown. SAM_H1377 (2 specimens): Southern margin, 28 km from Port Alfred/3 km off Old Woman’s Estuary, 33°30'00.00"S, 27°08'59.99"E; 93 m.

Description.

Corallum ceratoid to trochoid, firmly attached to substrate by a slender pedicel (PD:GCD = 0.3-0.7) that expands into a monocyclic encrusting base. Calice slightly elliptical (GCD:LCD = 1.1-1.3). Largest specimen examined (SAMC_A090140) 26.2 × 23.3 mm in CD, 9.6 mm in PD, and 48.1 mm in H. Costae flat to slightly convex, being prominent at calicular margin. Costae bear irregular and small granules. Intercostal striae thin and shallow. Both costae and intercostal striae become progressively faint towards base. Corallum white with theca being slightly light brown.

Septa hexamerally arranged in five cycles, sometimes the last cycle being incomplete, according to the formula: S1-3> S3> S4> S5 (96 septa). S1-2 highly exsert and equal in width, extending to columella with straight axial margins. S3 less exsert, 1/3 less the width of S1-2, but in larger specimens meet columella deeper in fossa. However, in smaller specimens (<13.0 mm in CD), S3 do not join columella and has a slightly dentate axial margin. S4 less exsert and ½ the width of S3, with dentate axial margin. S5 not exsert, rudimentary, with the most dentate axial margin. Fossa of moderate depth, containing a papillose columella composed of a group of 15-20 well-defined rods.

Distribution.

Regional: Western to eastern margin of South Africa, off Gansbaai extending towards Scottburgh; 36-365 m. Elsewhere: No other distributional records are known.

Remarks.

The species was first reported in South African boundaries by Gardiner (1904) as Caryophyllia capensis , and later tentatively placed in the genus Paraconotrochus (Cairns and Parker 1992). However, among the three genera ( Caryophyllia , Paraconotrochus , and Monohedotrochus ) only the latter lacks paliform lobes before S3. In addition, after examining Gardiner’s (1904: [fig. 4C]) illustrations, no pali were observed. Furthermore, the coralla of specimens examined display well-defined granular costae, whereas those of Paraconotrochus are generally smooth and costae absent or poorly defined. Based on these differences, we propose the new combination Monohedotrochus capensis (Gardiner, 1904). Within the examined material some are represented by small specimens (i.e., SAM_H3210 [Fig. 4K ] and SAM_H3211), which resemble Gardineria Vaughan, 1907 in having transversely wrinkled epitheca and outer septal margins being separated from calicular margin by a notch. However, juvenile Monohedotrochus capensis and Gardineria species are difficult to distinguish and thus these two samples (SAM_H3210 and SAM_H3211) are added here with caution.

Figures

Figure 4. A, B Heterocyathus alternatus (ORI _ DIIIe 1 _ 1, locality data unknown) A calicular view B lateral view C, D Heterocyathus monileseptatum sp. nov. (SAM _ H 1431, off Durban Harbour, 99 m) C calicular view D lateral view E, F Heterocyathus sulcatus (SAMC _ A 073123, off Shaka's Rock, 100 - 105 m) E calicular view F lateral view G, H Labyrinthocyathus delicatus (SAM _ H 2836, off East London, 146 - 238 m) G calicular view H lateral view I, K Monohedotrochus capensis comb. nov. I, J (SAMC _ A 088924, off Kidds Beach, 247 - 147 m) I calicular view J lateral view K (SAM _ H 3210, off Scottburgh, 690 m) calicular view L, M Polycyathus sp. (USNM 91677, off Port Dunford, 69 m) L calicular view M full view N, O Rhizosmilia robusta (USNM 91689, off Kosi Bay Estuary, 74 m) N calicular view O lateral view P Solenosmilia variabilis (SAM _ H 3158, off Cintsa, 630 m) P full view. Scale bars: 10 mm (A-G, I-O); 100 mm (H, P).